There have been proposed various types of processing devices that perform processes such as agitation, defoaming, and dispersion of a material to be processed. One of them is a type of device using a centrifugal force (hereinafter referred to as centrifuge). Patent Literature 1 discloses this type of centrifuge. In the centrifuge, an ultrasonic wave generation source with an agitating blade is inserted into an agitation vessel. Then, while ultrasonic waves are applied to the material to be processed, the agitation vessel is rotated around a rotation axis disposed in the vertical direction. The centrifuge configured as described above is considered to efficiently disperse the material to be processed.